Noveske's AR-15 Match Barrels feature their exclusive 5.56 Match Mod 0 Chamber, designed to offer outstanding accuracy with both 5.56x45mm NATO and 223 Remington ammunition. Composed of Cold Hammer Forged Steel, the bore is given improved polygonal rifling that slightly boosts projectile velocity and reduces the speed of the bore's erosion, meaning superior accuracy retention that outlasts that of barrels with conventional rifling. All Noveske match barrels have a bead-blasted satin finish, M4 extended feed ramps, and are threaded at the muzzle for the addition of flash hiders, muzzle brakes and/or sound suppressors. Each barrel is shipped with a pinned, low profile gas block, gas tube and barrel extension. Note: An "AR-15 Pistol" barrel is less than 16" in length. Pistol barrels are only for use on AR-15 pistol lowers and legal Short-Barreled Rifles. Other configurations may violate Federal law.